Solid state photolysis of inclusionmolecularcomplexes of N,N-dialkylpyruvamides with deoxycholicacid or cyclodextrin gave the corresponding β-lactams as main products. The chemo-, stereo- and regioselectivities of the solid state reactions were different from those of the reactions in solution. Asymmetric induction due to the chirality of deoxycholicacid or cyclodextrin was observed.